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The Skeletal system. The Skeletal System. An adult human skeleton consists of 206 bones. These include: - 22 Cranial and Facial Bones - 6 Ear Bones - 1 Throat Bone - 4 Shoulder Bones - 25 Chest Bones - 26 Vertebral Bones - 6 Arm and Forearm bones - 54 Hand Bones - 2 Pelvic Bones
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The Skeletal System • An adult human skeleton consists of 206 bones. • These include: • - 22 Cranial and Facial Bones • - 6 Ear Bones • - 1 Throat Bone • - 4 Shoulder Bones • - 25 Chest Bones • - 26 Vertebral Bones • - 6 Arm and Forearm bones • - 54 Hand Bones • - 2 Pelvic Bones • - 8 Leg Bones • - 52 Foot Bones
You need to know: • The functions of the skeletal system • The movement possibilities at hinge and ball & socket joints • Knee/Elbow • Shoulder • Understand how regular exercise benefits the skeletal system
Task • Read through the example of Tom Daley on pg 153. • Make up your own sporting example that shows all three functions of the skeletal system in action
What is a joint? A joint is a place where two or more bones meet
Joints • The human skeleton is jointed to allow movement. • Muscular contraction causes the bones to move about the joints. • The bones act as levers with the joints acting as pivots. A joint iswhere two or more bones meet andmuscles act together to cause movement.
Freely Moveable Joints • Freely Moveable joints are also known as Synovial Joints. • They are freely moving and occur where 2 or more bones meet. • There are about 70 freely moveable joints in the human skeleton. A typical synovial joint has the following characteristics: 1.Cartilage – A material which covers the end of each bone, and which helps prevent friction between the joint. 2.JointCapsule – The outer covering of the joint that holds the bones together and protects the joint. 3.SynovialMembrane – The inner lining of the joint capsule which also produces synovial fluid. 4.SynovialFluid – The fluid which surrounds the joint and acts like an ‘oil’, lubricating it to allow easy movement. 5.Ligaments – These are elastic straps which join bone to bone, holding the joint together. 6.Tendons – These are non-elastic straps which join muscle to bone.
Examples of Hinge Joints Elbow Joint Knee Joint These joints can be moved in the following ways: • Flexion (Bend) • Extension (Straighten)
Examples of Ball & Socket Joints Hip Joint Shoulder Joint These joints can be moved in the following ways: • Flexion (Bend) • Extension (Straighten) • Rotation (Circle) • Abduction (Move away from the body) • Adduction (Move towards the body)
Exercise and the Skeletal system • Bones continue to grow until about the age of 18 • Exercise can increase bone density • Ligaments and tendons become thicker and stronger aiding flexibility and power in movement • Young people must be careful not to do too much of certain types of exercise (long distance running/weight lifting) as this can can bones to grow irregularly
Importance of weight-bearing exercise and Osteoporosis • As people age their bones become lighter, less dense and can become weaker • In extreme cases they can break easily, this condition is known as osteoporosis
Importance of weight-bearing exercise and Osteoporosis • To avoid onset, appropriate activities such as walking, running, skipping and aerobics put pressure on bones increasing their strength. Other activities for more senior citizens that are not weight-bearing but are beneficial include swimming, cycling or aqua- aerobics
Diet & the Skeletal system • Eating a balanced calcium rich diet helps the bones grow & increase in density. • Found in Milk, Cheese & Yoghurt • Vitamin D is essential to growth and maintenance of healthy bones and helps with the absorption of calcium. • It is made by the body when the skin is exposed to sunlight • Smoking & too much alcohol have a toxic effect on bones
Injuries to the skeletal system • Research & make notes on the following using pages 158-160 • Injuries to Bones • Fractures • What is a fracture? • What are the different types of fracture? • Injuries to Joints • Tennis & Golfer’s Elbow • Dislocations • Sprains • Torn Cartilage
Fractures • A broken or cracked bone. • Occurs as a result of direct or indirect force.
Tennis & Golfer’s elbow • Overuse injuries to the tendons at the elbow joint. • The main symptom is pain on the elbow • Tennis – outside • Golf – inside You can develop these conditions even if you do not play these sports.
Dislocations • Where a bone at a joint is forced out of its normal position. • Often as a result of a hard blow which causes the bone to be displaced. • Symptoms include: • Deformity and swelling at the joint which is locked in position • If in any doubt, treat as a fracture
Sprains • A damaged ligament caused by wrenching or twisting. • One of the most common sprains in sport is a twisted ankle. • Symptoms: • Pain around the joint • Swelling • Visible bruising
Torn cartilage • Cartilage is a firm elastic substance found at the ends of the bones of a synovial joint. • Torn piece of cartilage moves in the joint and can become caught or wedged between the bones. • Symptoms: • Pain around the knee joint • Swollen knee • Difficulty in moving